LM139AJ Texas Instruments 4-Channel Comparator Open Drain, Open Collector O/P, 1.3 μs 36 V 2 V 14-Pin CDIP

Although comparators and operational amplifiers are superficially similar devices their operation in practical applications is very different. Op amps are intended for linear operation accompanied by suitable feedback whereas comparators are tailored for rapid switching and generally operated in open-loop mode. Dedicated voltage comparators have significantly shorter propagation delays and are capable of faster response times under saturated conditions. Most comparators are also more tolerant of high differential input voltages and many have open-collector outputs allowing parallel operation with other devices.